Fig. 1: Pathway depiction of how free and esterified oxylipins could form in heated oil.
From: Triacylglycerols are preferentially oxidized over free fatty acids in heated soybean oil

TAGs release FFAs which undergo oxidation to form free oxylipins (Pathway 1, blue arrow). Alternatively, polyunsaturated fatty acids on TAGs can be directly oxidized to form esterified oxylipins (Pathway 2 in red). The oxidized oxylipins on TAGs can be released to generate free oxylipins (Pathway 2 in red). Secondary oxidation products can be generated by the breakdown of free or esterified oxylipins32. TAGs Triacylglycerols, FFAs free fatty acids.